Factors associated with HIV and HBV co-infection in Northern Thailand

ObjectiveTo identify factors associated with HIV and hepatitis B virus (HBV) co-infection in Northern Thailand.MethodsWe tested 355 newly diagnosed HIV-infected subjects for hepatitis B surface antigen, hepatitis B surface antibody, and hepatitis B core antibody by using immunochromatographic and ELISA methods. Cases were positive for one or more of the HBV markers and controls were negative for all HBV markers. All study subjects were asked to complete a questionnaire to identify the associations between variables. We used logistic regression model to evaluate the associations between demographic and behavioral variables and HIV/HBV co-infection.ResultsA total of 41 cases and 83 controls were suitable to analyze in the study. Among them, 15.0% were males, 40.3% were 30–39 years old, 62.9% were married, 18.6% were illiterate and 89.5% were employed. Besides, 26 cases (23.4%) had a history of a blood transfusion, 12.9% had a history of jaundice, 29.0% had a CD4 cell count ≤ 200 cells/mm3, 0.8% were intravenous drug user, 29.8% tattooed, 64.5% had a body piercing, 12.1% were commercial sex workers, 11.3% had first sexual intercourse at age ≤ 15 years old, 6.5% were homosexual, and no one had a history of HBV vaccination. After controlling for all possible confounder factors in the multiple logistic regression model, we found two factors associated with HIV/HBV co-infection: number of years in school and CD4 cell count. Subjects with no education were more likely to have HIV/HBV co-infection, which was 7.07 times (odds ratio = 7.07, 95% confidence interval = 1.77–28.24) greater than those with 7 years of education group. Subjects with CD4 count ≤ 200 cells/mm3 were less likely to have HIV/HBV co-infection than those with a CD count ≥ 200 cells/mm3 (odds ratio = 0.35, 95% confidence interval = 0.13–0.94).ConclusionsOur findings suggest that having a good education and having a good immune status are a protective factor of HIV/HBV co-infection. A practical approach would be a provision of wide access to general and sex education on the risk and prevention of HIV, HBV, and a promotion of HBV immunization.